I think at the end of the day, no news is good news. If they sent all applications to Perth they'd have nothing to do at the Melbourne office.We applied april 2014 online in Vic too but never got an email apart from the acknowledgement and bridging visa. Is that a good or bad sign?
I assume they took a chunk and sent them over due to the Perth branch being able to support extra intake of applications. I wouldn't worry yourself.